1. Field of the invention
The present invention relates to a method of forming an automotive seat, and in particular relates to a method of forming a deep groove in the lateral surfaces of the seat during the forming process in which a covering member is directly bonded to a cushion body made of such material as urethane foam.
2. Description of the Prior Art
Reference is made to FIG. 1, which illustrates a conventional seat construction comprising a cushion body (101) made of such material as urethane foam or the like and formed by a mold in a predetermined shape, and a covering member (102) directly bonded to the cushion body (101) in an integral manner.
To form such integral seat body, a common method hitherto basically involved vertically pressing steps using a pressure die in order to bond a unitary sheet of the covering member (102) to the cushion body (101), while at the same time forming the desired shape of seat.
However, difficulty exists when the prior art method is utilized for forming the above-mentioned seat whose cushion body (101) includes lateral walls (103) which are tapered downwardly, because the vertically pressing steps are limited to the vertically directed bonding. They are not suited for bonding a lateral side portion (102b) of the covering member (102) to the corresponding lateral walls (103) of the cushion body (101).
Further, entirely bonding the covering member (102) to all outer surface areas of the cushion body (101), including their respective lateral portions, deteriorates the elastic cushioning effect of the seat.
Another drawback in the above-mentioned prior art method is that the lateral side portion (102b) of the covering member (102) lies loosely away from the cushion body (101), as in the phantom line of FIG. 1. After the seat is assembled, the portion (102b) is merely secured at its lower part to the seat and will be distorted into a slack state when an occupant sits on the seat, which consequently impairs the aesthetic appearance of the seat. In addition, the resultant seat has no attractive characteristics for commercial value, because of its simple arrangement of the cushion body (101) and the covering member (102) being merely mounted on a seat cushion frame (104), as understandable from the FIG. 1.